Communications technologies and uses have greatly changed over the last few decades. In the fairly recent past, copper wire technologies were the primary mechanism used for transmitting voice communications over long distances. As computers were introduced the desire to exchange data between remote sites grew for many purposes, such as those of businesses, individual users and educational institutions. The introduction of cable television provided additional options for increasing communications and data delivery from businesses to the public. As technology continued to move forward, digital subscriber line (DSL) transmission equipment was introduced which allowed for faster data transmissions over the existing copper phone wire infrastructure. Additionally, two way exchanges of information over the cable infrastructure became available to businesses and the public. These advances have promoted growth in service options available for use, which in turn increases the need to continue to improve the available bandwidth for delivering these services, particularly as the quality of video and overall amount of content available for delivery increases.
As the consumer electronics industry continues to mature, and the capabilities of processors increase, more devices have become available for public use that allow for the transfer of data between devices and more applications have become available that operate based on this transferred data. Of particular note are the Internet and local area networks (LANs). These two innovations allow multiple users and multiple devices to communicate and exchange data between different devices and device types. With the advent of these devices and capabilities, users increasingly desire to receive a variety of services over these networks. Some common examples of these services (or applications) are video on demand (VoD), Internet Protocol television (IPTV) and audio files. Additionally, many of these services can be received in different formats, relating to different service quality levels, based upon a variety of parameters.
Taking advantage of the ongoing improvements to communications, a single user or users within a household can have various devices that are capable of interacting with other devices and/or systems through various networks. It is not uncommon for a household to have personal computers (PCs) 10 and 12, a cell phone 14 and a personal digital assistant (PDA) 16 all of which are capable of connecting to a wide area network (WAN) 22 through different interfaces as shown in FIG. 1. In this example, PCs 10 and 12 are part of a home local area network (LAN) and are connected to a network access translation (NAT) router 18 which is part of customer premise equipment (CPE) gateway (GW) 20, for example, a digital subscriber line (DSL) modem or a cable modem. The NAT router 18 (or similar device using network access port translation (NAPT)) receives a single WAN IP address which is shared by all of the devices associated with the NAT router's 18 LAN. To differentiate between devices in its LAN a typical NAT router 18 uses Address Resolution Protocol (ARP) to obtain the Medium Access Control (MAC) addresses (given the locally assigned IP addresses from reserved private IP addresses, e.g., 192.168.x.x) of the devices, e.g., PCs 10 and 12 which are then stored. Packets can then be transmitted by these locally addressed devices, e.g., PCs 10 and 12, by using ARP and layer 2 switching. This layer 2 switch could be located in CPE GW 20 or elsewhere in the network. This then allows the CPE GW 20 with router 18 to provide access for the devices to a WAN 22 by forwarding traffic to IP edge node 26 associated with WAN 22. When local traffic is outgoing to the WAN 22, the packets pass through the NAPT function in the router 18 wherein the local address is replaced by a WAN address in the IP source address field. In the opposite direction traffic from IP edge node 26 is received by CPE GW 20. The received traffic then goes through the NAPT function within router 18 where the WAN address is replaced by the local address in the IP destination address field. The router 18 within CPE GW 20 knows that this traffic address belongs to the local subnet, i.e., from the matching prefix, and that this local subnet is a LAN of an Ethernet type. The ARP protocol can then be used to find the Ethernet MAC address of the device (alternatively the Ethernet MAC address of the device associated with the incoming traffic can be stored from the initial use of the ARP protocol). For more information regarding ARP, the interested reader is referred to RFC 826 and RFC 4338 which can be found online at www.ietf.org. The received traffic is then forwarded to the MAC address. From here traffic from the PCs 10 and 12, after the desired authentication and approval process, goes to and can be received from their desired respective correspondent nodes (not shown).
Also as shown in FIG. 1, other household devices can be in communication with correspondent nodes (not shown) associated with WAN 22. For example, cell phone 14 and PDA 16 can have a wireless connection to cellular network 24 which represents any of the different types of cellular networks and the infrastructure used to connect the cellular network 24 with WAN 22, which in turn is in communication with an IP edge node 28 associated with the WAN 22. At this point, traffic from cell phone 14 and PDA 16, after the desired authentication and approval process, goes to their desired respective correspondent nodes (not shown). These devices, cell phone 14 and PDA 16, are considered to be WAN addressed devices since they are directly assigned their own WAN IP address, e.g., cell phone 14 can be assigned a WAN IP address of, for example, 178.12.13.15 from a source associated with WAN 22, e.g., a dynamic host configuration protocol (DHCP) server. These WAN addressed devices do not share their IP address with any other devices, i.e., a single unique IP address is associated with each WAN addressed device. Typically WAN addressed devices desire their own IP address from a WAN due to being mobile and/or the device or service desired requires a type of special service or policies that are difficult to support when “hidden” behind a NAT router. Since FIG. 1 is showing a simplified communications diagram, it is to be understood that there typically would be a plurality of routers (not shown) within WAN 22 through which communications between these devices and their respective correspondent nodes (not shown) travel. This concept also can apply to the travel path for mobile communications enroute to an IP edge node 28 from their respective originating points.
As shown in FIG. 1, not all of the communication devices are operating within the same LAN at the user's household. This means that the locally addressed devices, e.g., PC 10 and PC 12, are not locally communicating directly with the WAN addressed devices, e.g., cell phone 14 and wireless PDA 16. It would be useful to have the option to connect the WAN addressed devices to the LAN and allow these WAN addressed devices to communicate directly with other devices connected to that LAN, as well as reducing the load on the wireless access system.
However, there are currently reasons for not assigning local addresses to WAN addressable devices. For example, for some devices, typically non-stationary devices, it is not desirable to have them operating in a locally addressed mode because a user often wants a device to be reachable from the WAN side to continue to receive all of the same services currently receivable, e.g., cell phone 14 needs its WAN address to typically receive all of their subscribed services from the cellular network 24. Also, if one were able to force all of the devices to have a unique WAN address, the desired number of IP addresses might not be available since there is a cap on the number of available addresses in IPv4. Additionally, there are currently hurdles for putting both locally addressable devices and WAN addressable devices into the same LAN, for example, most CPE GWs 20 available today are designed to operate in either a locally addressable mode for all connected devices or in a WAN addressable mode for all connected devices. When attempting to put both locally addressed devices and WAN addressed devices into the same LAN there need to be methods for the CPE GW 20 to determine when it should allocate IP addresses, when the accessed WAN 22 should allocated IP addresses to devices as well as how to route packets between devices that are locally addressable and those devices that are WAN addressable.
Accordingly the exemplary embodiments described herein provide systems and methods for allowing locally addressed devices and WAN addressed devices to be part of the same LAN for improving communications between these devices.